Risdiplam Treatment Results in Independent Sitting in Children With Spinal Muscular Atrophy in Phase 2 Study

A proportion of infants with spinal muscle atrophy (SMA) sat independently for at least 5 seconds after treatment with risdiplam (Genentech, San Francisco, CA). These results are from the pivotal part 2 of the Firefish study (NCT02913482). The primary outcome measure of the study was the proportion of infants sitting without support for at least 5 seconds at 12 months of treatment. The infants were assessed with the gross motor scale of the Bayley scales of infant and toddler development-third edition. Safety for risdiplam in the Firefish study was consistent with its known safety profile, and no new safety signals were identified.

More than 400 individuals have been treated with risdiplam across all studies, with no treatment-related safety findings leading to study withdrawal in any risdiplam trial. The study evaluated infants age 1 to 7 months with type 1 SMA.

“This large, global trial confirms the efficacy of risdiplam in an advanced and difficult-to-treat population, including many infants whose disease had already progressed significantly before starting treatment,” said Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development. “We are very encouraged by these results and we look forward to sharing them with regulators. We also thank the entire SMA community for their continued partnership.”

Risdiplam is being studied in a broad clinical trial program in SMA with individuals ranging from birth to age 60 and includes individuals previously treated with other SMA-targeting therapies. The clinical trial population represents the broad real-world spectrum of people with SMA, with the aim of ensuring access for appropriate individuals.